Yes, the CPU will be the limiting factor in some CPU intensive games, like Battlefield 1 with 64-players and The Witcher 3 in Novigrad city, especially at lower resolutions. Other times however, such as the majority of the gameplay in The Witcher 3, will still be GPU limited. Also, please note that some games will not even start up on a 2-threaded CPU. (Far Cry 4, Far Cry Primal and Titanfall 2 are all examples)